There are a large number of places where steel tread plate is used and, in fact, where it is required, such as on steps, decks and walkways on earthmoving equipment or railroad engines, on bridges, on cranes, and the like. Its use is dictated by its strength and by its ability to have its surface corrugated, roughed or distressed so as to provide an anti-skid, gripping surface. In the past, the desired anti-skid, gripping surface characteristics have been accomplished, particularly under reasonably ideal conditions. However, under footwear containing heavy mud, or under mud, water and freezing conditions, the corrugated, roughened or distressed surfaces may become clogged or packed with mud and/or ice and become dangerous.
Many of the prior art devices have openings which do provide a cleaning function, but they are shaped in a way that the mud and the like compact in the openings, clogging the openings and rendering the tread less than 100% effective.
Some prior art devices have a continuous edge for the contact surface of the tread which edge can become iced and slippery.